std::string outputString = "";
  std::stringstream outputStringStream(outputString);

  outputStringStream << std::fixed << std::setprecision(4) << sum;
  std::string first;
  outputStringStream >> first;
  std::cout << first << '\n';
  std::cout << ch1 << " " << v1 << '\n' << ch2 << " " << v2;